SUMMARY ABSTRACT Significance. One third of women worldwide have experienced lifetime physical and/or sexual intimate partner violence (IPV). IPV is associated with numerous health problems for survivors and exposed children. Given the high global burden of IPV against women, the United Nations endorsed Sustainable Development Goal 5 (SDG5), to empower women and girls, in part by eliminating all forms of violence against them. Despite this mandate, common instruments to measure IPV have not been rigorously validated across place and time, leaving researchers and policymakers without clear guidance on the best methods to monitor trends in IPV or to assess the impacts of prevention programs. Aim. We propose to conduct a rigorous psychometric assessment of the domestic violence module (DVM) of the Demographic and Health Survey (DHS), the most common module to measure IPV in lower-income countries (LICs), and a similar IPV scale used across a consortium of organizations conducting IPV prevention trials (IPV-Tr). We will assess the ?measurement invariance? of items in the DVM and IPV-Tr, to determine how similarly the items function across geographies, over time, and across intervention arms. Data. We will leverage data from DHS undertaken since 2010 in 33 LICs that administered 18 similar items on emotional IPV (including controlling behavior), physical IPV, and sexual IPV to ever-partnered women of reproductive age and from 3 randomized trials using a similar, but shorter module. Methods. First, we will assess the (a) cross-national (N=33 countries) and (b) cross-time (N=5 countries) measurement invariance of 18 items related to women?s experiences of physical, sexual, and emotional IPV including controlling behaviors. We also will explore national and study-related characteristics that may account for any detected non- invariance in the items. Second, we will assess the within-trial (N=3 countries) cross-arm and cross-time measurement invariance of 8 items (IPV-Tr) used to measure women?s experiences of physical and sexual IPV in randomized IPV prevention trials and assess the impact of measurement non-invariance on determination of intervention impact. Third, we will assess the impact of within-trial (N=3) cross-arm and cross-time measurement non-invariance of items measuring IPV and depressive symptoms (DS) on tests of intervention impact on DS and the potential mediating role of DS within the treatment ? IPV relationship. We will test these three aims using multiple-group confirmatory factor analysis, multiple-indicators multiple-causes models, multilevel confirmatory factor analysis, and multilevel structural equation models. Innovation. This study is the first to test the measurement properties of the most common module to measure IPV in LICs and the impact of measurement non-invariance on IPV prevention trial findings. Impact. Results will provide critical insights to national statistical offices, ministries, bilateral/multilateral agencies, and intervention researchers on the most useful methodology to measure physical, sexual, and psychological IPV to monitor SDG5 with existing IPV scales. Results also will inform future studies to improve the measurement properties of these important scales.